NREL Energy Systems Integration Facility

The National Renewable Energy Laboratory (NREL) wanted the Energy Systems Integration Facility (ESIF) on their new campus to reflect their commitment to sustainable energy solutions. But cooling a high-density data center and conditioning sophisticated laboratories without using a lot of energy is very challenging. Integral Group assisted NREL throughout design development in facing these challenges to create the world’s most energy-efficient data center to date.

We determined that in Colorado’s climate, compressor-free cooling could be used in the ESIF data center year-round. We designed low-approach cooling towers to supply medium-temperature (71°F) chilled water to the server rooms. The medium-temperature water cools both the high performance computing (HPC) system and the rest of the servers in the data center, eliminating the need for expensive and failure-prone chillers.

In the data center, Integral Group designed rear-door heat exchangers to cool the servers. These cooling coils trap the hot air exhausted by the servers and immediately cool it with the medium-temperature chilled water. As a result of this careful design, the ESIF data center operates at a power usage effectiveness (PUE) of 1.06.

ESIF’s office and laboratory areas were also designed to conserve energy as well. A moderate window-to-wall ratio, increased floor and roof insulation, and triple-element windows improve the Facility’s insulation value, and contribute to the thermal comfort of NREL’s employees. Additionally, the heat that is generated by the HPC is harvested and used to heat the offices and labs, reducing the heat load for the facility.